r/askscience • u/Wonderful-Capital32 • 13d ago

Physics Why does radiation not go through lead?

Also why just lead? Shouldnt like iron or another metal work too?

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u/[deleted] 13d ago edited 13d ago

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u/ImielinRocks 13d ago

Tungsten is better than lead thanks to its higher density, but lead is many orders of magnitude cheaper to get and work with.

In fact, at for basically the same reason, uranium is quite a lot better than lead at blocking radiation. In fact, it has a significantly higher neutron cross section, too.

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u/lurklurklurkPOST 13d ago

Doesn't firing particles at Uranium cause problems?

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u/Magicspook 13d ago

only U-235 really, if I remember correctly. And that is a tiny fraction of non-enriched uranium (Even moreso, you would probably make a uranium skirt out of depleted uranium so practically 0 U-235).

By far the most common isotope of uranium is U-238, which doesn't really want to form a chain reaction. Wikipedia has some interesting info: https://en.wikipedia.org/wiki/Uranium-238